Process of extracting manganese from lean ores.



EDWARD W. .HASLUP, F BRONXVILLE, NEW YORK, AND BENJAMIN A.- PEACOCK, OF PHILADELPHIA, PENNSYLVANIA; SAID PEACOCK ASSIGNOR TO SAID HASLUP.

PROCESS OF EXTBACTING MANGANESE EROM LEAN ORES.

No Drawing.

To all whom it may concern:

Be it known, that we,'EDwARn W; HAVS- LUP and BENJAMIN A. PEACOCK, both citizens of the United States, residing, respectively, at Bronxville, Westchester county, New York, and Philadelphia, Philadelphia county, Pennsylvania, have invented certain new and useful-Improvements in Processes of Extracting Manganese from Lean Ores;,

and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process of extractmg manganese from 1ts lean ores and has for its object to improve the-methods heretofore proposed.

With this and other objects in view the invention consists in the novel steps and combinations of steps constituting the procpliances, that they are commercial failures under normal condltions.

Likewise processes employing sulfuric acid or other acids have frequently failed due to the low content of the manganese in the ores, to the comparatively low temperature at which, or to the comparatively short time during which the acid has acted, to the fact that it was not practicable to prevent the acid from attacking the containing vessels, or to a combination of these causes.

()n the other hand, there are many lean manganese deposits often in the form of sands, or clays, in which a large proportion -of the manganese is present as a hydrous oxid, a silicate, etc., and in which a crystalline structure has substantially disappeared. These deposits offer an attractive field for an acid process such as that disclosed below in which the above objections are avoided.

Further, these ores contain in addition to their tenor of manganese, more or less com- Specification ofietters Patent.

bined potassium and aluminum, and also frequently zinc, nickel, cobalt, copper, tung- Yatented Sept. 17,1918.

Application filed November 7, 1917. Serial No. 200,812.

sten, and other substances of a greater or less commercial value when the process employed is capable of economically recovering the same. The mineral psilomelane is a familiar example of an ore suitable" for the right kind of an acid'processin that it is a hydrous manganese-manganate in which a part of the manganese has been replaced by barium or potassium, so that it varies in composition, is generally more -or less impure and cannot be worked by many processes, while it readily lends itself to the acid process to be disclosed below. In chemical charactersthis said mineral may be written as MnO (Mn,K,Ba)O.nH,O. The material known as Wad is also an important oreof manganese suitable for a proper acid process that is not too costly. It occurs in amorphous and reniform masses either earthy, or compact. It is usually very soft'and often loosely aggregated. It is probably a more or less alterated product of pyrolusite, psilomelane and other minerals.

Further, the gangues of manganese ore bodies arefrequently more or less micaceous and therefore, alteration products resultingfrom decomposition of these said gangues' by an acid, materially add the value of the combined potassium recovered and of other compounds of a greater or less commercial importance to the .value' of the original manganese bearing material. When manganese dioxid MnO as well as most. of the other compounds of manganese, are treated with strong sulfuric acid at temperatures above 100 C. substantially all the manganese present goes into solution, with the formation of manganese sulfates.

At the same time substantially all, the alkali metals present, as well as more'or less of the aluminum, copper, zinc, etc., present also form sulfates. But unless the objections above mentioned to the prior acid processes can be overcome. these desirable features cannot be utilized in a commercial acid process. One way of overcoming these objections has been to employ only hand picked or refined manganese ores, but the hand picked, as well as the refined manganese ores of commerce do not have any considerable mineral content other than manganese, and therefore the ores of a low'manganese content, and marv offering physical objections After the desired constituents of the cannot be utilized for a hand picked or other prior process. On the other hand, the raw "ores, at times, may contain as much as seven per cent. of potassium oxid K 0, two per 5 cent. copper o'xids, and three per-cent. oxid of tungsten, much of which can be saved'by.

the process now to be disclosed. I

In carrying out this invention we may, for example, take the ordinary run of mined manganese ores, which may be too lean in manganese to be capable of commercial working by prior processes, and add predetermined quantities of other ores, to be disclosed below, whereupon we grind the'mixture to say 50 mesh, and without any addition of water to the finely divided material we then add Jsuflicient'sulfuric acid in excess to convert to the sulfates all the values it is desired to extract, but notsuflicient to convert the iron present. The resulting -mixture or magma is next discharged into a closed receptacle or den where'it is held for say 24 to 48 hours, and protected from rapid cooling by the thick non-metallic nonheat-conducting walls of the den or by other means. Owing to the conservation of the heat evolved and to the time the acid is allowed to react, as well as to the regulated quantity of acid employed, the said acid acts substantially completely and with the greatest economy.

It also acts, in a sense selectively, because owing to its limited quantity .it attacks the most reactive metals first and the least reactive last, and the latter in a minimum of quantity. v

In this way we are enabled to convert to sulfates substantially all the. manganese present in the mixed ores, even though these constituents of the. ore are in proportions too lean to be commercially worked by prior processes. At the same time no considerable proportion of the iron oxid present being attacked, the latter remains with the insoluble residue.

mixed ores have been converted into crude sulfates, the latter are extracted with water, and the values in the solution thus obtained are recovered by any suitable well known methods,'such as by concentration and fractionation, or by precipitation and fractionatiom 4 It will thus be seen that an important feature of this process resides in utilizing the chemical heat generated over a long period of time to raise the mass to the reacting temperature. The receptacle being closed, the heat is conserved, is allowed to generate more heat and thus the acid is used up in a most economical manner. In fact, the temperature often rises in the mass to a point between 200 C. and 300 (1., which 3. greatly promotes the attack by the acid of accumulate while new reactions start, which.

memos I sulfuric acid to raise the latter to a higher temperature, and therefore to attack with greater vigor the more electro positive metals present in a combined state. The heat thus generated immediately raises those combined metals which are less electro-positive to a. reacting temperature, and the heat generated from the attack on said last mentioned metals. serves to still further raise the temperature of the mass, with the result that the reaction proceeds to a completion with an. amount of acid which would be impossible if an ordinary autoclave form of vessel were employed, or if added free water or other dilutents were present. This principle becomes important when it is remembered that the artificial heating ofthe mass would not accomplish the same purpose, because sulfuric acid under such heating would. be volatilized, and would fail to completely decom pose the less electro positive metal compounds. I

In very lean manganese ores such as are contemplated by this process, there is generally present an insuflicient quantity of the more electro positive bases, such as mang'anese, potassium, etc.,to liberate the necessary heat to raise the mass up to a' temperature at which the less electro positive compounds would be attacked, and, therefore, the-reaction or process will fail to be commercial unless this defect is avoided. In such cases we add an ore containing a compound which is readily attacked by sulfuric acid at. ordinary temperatures and also yields a valuable by product, and we thus raise the temperature to a point sufficiently high for the other constituents to be attacked, while at the same time obtaining aby-product of a value sufficient to make the process commercially successful.

That is to say, suppose, for example, the manganese should be present in the ore, in quantities of only about three per cent. or four per cent, and suppose the potassium should be present in like small quantities. Then no matter how high one may heat the mass artificially the reaction would not be a commercial success.

add the mineral known as pyrophyllite hav ing a composition of say H Al (SiO emma which forms with the sulfuric acid an alu minum sulfate also constituting a valuable by-product.

In either case, a very considerable quantity of heat is at once liberated, and this .in the State of Virginia, andwhich may be said to have a composition varying substantially as follows Sample Sample No. 1. No. 2.

, Per cent. Per cent.

. 11 p 11 11 6 6 7 5 2 v 41 34 40 1 1 1 1 l 1 After finely subdividing the said clay of I sample #1, we add sufiicient sulfuric acid,

slightly in excess, to unite with all of the MnO the K 0, the Ca() and the MgO present, but not enough to unite with the iron, the aluminum or other constitutents present. In the case of a clay having as much manganese and potassium as is indicated in said sample #1, the addition of very little, if any serpentine, or other mineral, will be found necessary, but a little serpentine will greatly improve the process. In such cases, after the mass has been confined for a period of say 24 to 48 hours, the crude sulfates of manganese, potassium and magnesium are readily separated out and recovered in the manner stated. On the potassium are not present in sufiicient proportions as is the casein sample #2, we may then add any suitable quantities of serpentine, or other minerals, which contain constituents that are readily attacked by the sulfuric acid and which provide valuable byproducts, and we proceed in the manner above disclosed.

The quantity of serpentine or other minerals added will in each case depend upon the leanness of the manganese ore, the quality of the serpentine, and the amount of byproduct it is desired to produce. But, in so far as maintaining the reaction is concerned, any quantity may be added which will bring the total quantities of manganese and magnesium in the charge above say 10 percent. or 15 per cent. In'our copending application #200,813, filed Nov. 7, 1917, entitled Process of extracting values from manganese and other ores, we have disclosed and claimed a process similar to the one above outlined, except no addition of serpentine or other similar ores is contemplated.

It is obvious that this process is not confined to the recovery of manganese from its ores nor to the use of sulfuric acid, for it may be applied to other minerals and with other acids. Therefore, we do not Wish to be limited to the above disclosure except as may be required by the claims.

What we claim is 1. The process of extracting values from lean ores capable of being leached with sulfuric acid which consists in finely dividing said ores; adding to said ores in a. finely divided state other minerals containing a constituent which is capable of reacting exothermically in the process; mixing the finely divided ore material devoid of added free water with an acid; transferring the mixed ore and acid to a closed receptacle also devoid of added free water, and from which a substantial portion of the heat of reaction is prevented from escaping; holding the reacting mass in said receptacle for a period of more than fifteen hours; extracting the reaction products from the residue; and recovering the desired values from said products, substantially as described.

2. The process of extracting values from lean ores capable of being leached with sulfuric acid which consists in finely dividing said ores; addin to' said ores in a finely divided state ot er minerals containing a constituent which is capable of reacting exothermically in the process; mixing the finely divided ore material. with sulfuric acid; transferring the mixed ore and acid to a closed receptacle, from which a substantial portion of the heat of reaction is prethan twenty hours; extracting with water the reaction products from the residue; and recovering the desired values from said products, substantially as described.

3.-The process of recovering manganese values 'from lean ores which consists in adding to said oresother minerals containing a constituent'that is capable of reacting exothermically with sulfuric acid; finely dividing said mixed ores; mixing the finely divided ore material with a limited quantity'of sulfuric acid; transferring said ore devoid of added water and mixed with-said acid to a closed container from which a substantial portionof the heat of reaction isprevented from escaping; confining the mass in said container until the accumulated heat Y has caused substantially all the manganese present to be converted into the form of sulfates; extracting. said sulfates with water;

and recovering the manganese values from the solution thus obtained, substantially as described.

4. The process of recovering manganese and other values from lean mangamferous ores which consists in adding other minerals ceptacle from which the heat of reaction is prevented from escaping; extracting the re- I sulting sulfates with water; and recovering desired values from the solution thus obtained, substantially as described.

5. The process of recovering manganese and other values from lean ores which consists in adding another mineral containing combined potassium to said ores finely di viding the mixture; adding sulfuric acid in a limlted quantity to the finely divided ore; confining the ore devoid of added free water mixed with said acid in a closed receptacle from which the heat of reaction is prevented from escaping until the desired values have 6. The process of recovering manganese and other. values from lean ores which con-- sists in adding another mineral containing combined potassium to said ores; finely dividing the mixture; adding sulfuric acid of a gravity'not more than B., in a limited quantity to the finely divided ore; confining the ore devoid of added free water mixed with said acid in a closed receptacle from which the heatof reaction is prevented from escaping until a temperature above C. is reached and until the desired values have been transformed into sulfates; extracting said sulfates with water; and recovering said values from the solution thus obtained,

substantially as described.

In testimony whereof we afiix our signa-- tures. Y EDWARD W. HASLUP.

BENJAMIN A} PEACOGK. 

